//喝汽水，1瓶汽水1元，2个空瓶可以换一瓶汽水，给20元，可以喝多少汽水（编程实现）。
#include <stdio.h>
int main()
{
    int money = 20;
    int bottle = 0;
    int count = 0;
    count += money;
    bottle += money;
    money = 0;
    while(bottle >= 2)
    {
        int ret = bottle/2;
        count += ret;
        bottle %= 2;
        bottle += ret;
    }
    printf("可以喝%d瓶汽水", count);
    return 0;
}